Referring to FIG. 1, a conventional prosthesis 10 includes a prosthesis socket 60 into which the amputated limb is placed. The prosthesis socket 60 is connected to a prosthesis shank 30. The prosthesis shank 30 is further connected to a prosthesis foot 20 which bears the weight and makes contact with the ground. The conventional prosthesis 10 includes an adjustable connection, normally between the prosthesis socket 60 and the prosthesis shank 30. For example, the prosthesis shank 30 can have a coupling 40 with an upper end having a concave hemispherical surface. The prosthesis socket can have a pyramid adaptor 50 at the lower end thereof which fits into an aperture provided in the concave surface of the coupling 40. The pyramid adapter 50 includes a surface curved to match the concave surface of the coupling 40. With this configuration, the prosthesis socket 60 can be articulated forward and backward and from side to side with respect to the prosthesis shank 30 and foot 20 to align the prosthesis socket 60 and prosthesis shank 30 to an optimal position that is both efficient and comfortable for the wearer of the prosthesis 10.
A computerized prosthesis alignment system is disclosed in U.S. Application Publication Nos. 2008/0139970 and 2008/0140221, incorporated herein expressly by reference for all purposes. These application publications disclose a torque sensor 104 and control module 106 that provide a means for manually aligning a prosthesis. See FIG. 4 of the publications. The torque sensor 104 is incorporated with a pyramid adaptor (see FIG. 6A of the publications) that then attaches to the lower part of the prosthesis socket 60 and is capable of measuring forces experienced by the prosthesis socket 60. A computer system is then able to analyze the forces and provide feedback to a prosthetist via a graphical user interface, in the form of specific instructions for aligning the prosthesis to an optimum setting. For example, because the alignment of the pyramid adaptor is adjusted using four set screws (elements 117a-d in FIG. 5 of the publications), the computer system can provide instructions, such as the amount of turns required of the set screws to achieve the proper alignment.
The referenced publications further disclose a method of maintaining the alignment once the optimal alignment is achieved. This method relies on the use of a substitute pyramid adaptor that is dimensionally similar to the torque sensor so that it can simply be substituted for the torque sensor. (See element 105 in FIG. 5 of the publications.) The method, however, relies on removing the set screws that hold the alignment according to a specific sequence so as to transfer the substitute pyramid adaptor for the torque sensor without upsetting the previous alignment.
While the above-described computerized prosthesis alignment system is a significant advance in this art, new improvements are continuously being sought that enhance the ways in which a prosthesis can be aligned.